We propose to hold an international conference involving approximately 300\scientists from the U.S. and abroad. We envision that 10 major topics will be addressed; that approximately 30 scientists working in the field will present major scientific addresses; and that 10-15 other scientists working in the subject area will be invited to chair sessions, serve as discussants, etc. Poster sessions will enable other participating scientists to present their results. As our knowledge of the interlocking roles of mutational changes in genes and the development of cancers has incresaed, it has become increasingly clear that antimutagenesis and desmutagenesis could have significant roles in lowering cancer incidence. This conference is designed to discuss the current state of our knowledge of mechanisms of antimutagenesis and anticarcinogenesis in simple and complex systems, and to aid in establishing directions for future research in this important area. The complete Proceedings will be published in edited book form and a summary of conference highlights will be published in an edited specialty journal within 6 months of the conference. Participating sponsors will be acknowledged in the Conference program as well as in the resulting book and review. The major objectives of the conference are: (1) to bring together scientists working at the molecular/mechanistic level in the fields of antimutagenesis and anticarcinogenesis in order to enhance knowledge in these fields; (2) to rapidly disseminate a thorough, current summary of a promising research area directed at a preventive rather than a curative stage of genetically related illnesses.